Swivel-caster



Patented @c u', w21.

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UNll'ED ya TES Aralar orifice.

SWI'VEL-CASTER.

To nl] yfc/i om 'it m (z z/ concer/n u 1 Be it known that l, floiiN Lonoinn ones Y, Nrrr'r, a citizen ot the United tntates or America, and resident of Long` Beach, Los

.qualities and beingr relatively simple'in construction and inexpensive ot' n'iaiiuiacture.

il; :further ob]ect of this invention is to provide improved means for connecting the top plate to other caster parts.

A 4further object ofv this invention is to provide an improved swivel caster havingr a double row of bearing' balls, one receiving vertical pressure only and the other lateral pressure only., each ot said rows ot' balls being of relatively large diameter.

A further object of this invention is to provide a swivel caster having improved means ol connection between svvivelinp,- and stationary members, permitting relatively large ball race for the balls receiving lateral pressure and acting as an autiti'iction re-l tainer of the swiveliiig member thereby7 reducing leverage and consequent strain, friction and Wear.

A further object ot invention is to provide a swivel caster having' separable or detachable parts, thus facilitatingw renewal of Worn or broken` members.

A further object of this invention is to produce. a swivel 'caster adapted to be attached to a fiat surface and havinga high degree of swivelingif elliciency so that the supporting wheel may be set very near to the vf i al axis of the device. thus reducing strain and ivear on the parts in ilse.

A further object ot this invention is to provide an improved swivel castor having` eliicient anti-friotion connecting; means between the stationaryand swivelinoparts,

contributing to case of operation and long life of the parts.

A further object of this invention is to provide an improved svviveling construction tor a caster' adapted for easy connection to further Fig. (i is a vertical section illustrating the" Specification of Letters Patent. Patented @015 119 1921 Application led April 3), 1921.

Serial No. 4=$5,886.

wheel carrying yokes or members ofyarious sizes and shapes and designed yto carry one. wheel or multiple Wheels of any desired size and shape, thus permitting an economical adaptation oi the caster to a Wide variety ot' uses and conditions.

A. further object of this invention is to provide an improved swivel caster having ample Storage capacity for lubricating 1grease affording constant lubrication over long periods.

With these and other objects in View, my invention consists in the construction, arrangement and combination of elements hereinafter set forth, pointed out in my claims and illustrated by the-accompanying drawing, Vin which- .ligure l is a vertical section of a swivel caster embodying my invention and showing one means for connectingthe containing member or shell to the top plate.

lF 2 is a vertical section oi a part ot' the device showinga different connecting means.

Fig'. 8 is a vertical section showing still. further connecting means.

Fig. 4: a plan View illustratimgg` both of ie forms of connecting means shown' in Tigs. 2 and 3i Fig. 5 is a vertical section illustrating a modied iorm of connecting means.

top plate and centering disk formed integrally by casting.

In the construction nl the device as shown particularly in Fig. l, a Wheel l0, which may be ot' any desired and suitable construction, is rotatably mounted in a Wheel yoke comprising.r spaced forks or Wings 1l, one of which is shown, and a. plate or top l2, which is substantially horizontal, partici larly in its central portion. The Wings 1l preferably taper toward their lovver ends and the axis of rotation of the Wheel l0 is arranged at tbe rear of the vertical airis' of tbe device so'tliat the Wheel trails in use, thereby automatically inducing swivelingz,- of the caster when the direction of travel is changed. The plate 12 preferably is formed with a downwardly extending flange 13 at its forward side, connecting the upper ends of the 'wings l1, and also preferably projects rearwardly beyond the rear marvins of Said wings and in overliangin'g vrelation to the wheel, at the point indicated by the numeral 14. This construction nfreatly strengthens the Wheel yoke." A swive ing retaining member of circular form is provided, comprising a central substantially plane portion 15 having an upwardly and outwardly flared peripheral portion 16, of annular form. The central portion 15 ot the retaining member is mounted on the central portion of the top 12 of the Wheel yoke and is rigidly secured thereto by a central bolt 17 or other suitable securing member. lf desired thecentral portion 15` of the retaining member may be formed at its center with a. downwardly projecting boss extending within a countersink in the top member 12, to assist in keeping said members centered and to take some of the lateral strain trom the member 17. The flaring portion 16 of the retaining member extends within a cylindrical shell 18, formed at its lower end with an inwardly directed peripheral Hangs 19 extending beneath said llared portion. IThe flange 19 is grooved or downset at its inner margin to form an annular raceway Jfor a series ot bearing balls 20, which also contactV the lower surface of the flared portion 16 of the retaining member. The inner portion of the flange 19 and outer portion of the flared portion 16 extend beyond the row ot balls 2O on lines spaced from and substantially parallel with horizontal lines tangential to said balls, and each of said members contacts said balls, under normal conditions, only on curved surfaces having radii at substantially forty-five degrees to the vertical axis of the device. Because of this ar rangement, there is, except possibly under very unusual circumstances, no downward pressure on the balls 20, which are designed to receive lateral strains only and not to vcarry any of the load.`

The shell 18, which is comparatively shallow, is formed at its upper end with an outwardly extending horizontal flange 21.'

A top plate 22 is provided and is mounted on and secured in any suitable manner to the horizontal flange 21. The top plate 22 is countersunlf in its central portion, into the space bounded by the upper end oft the shell 18, and within the limits of said shell said top plate is imperforate. A centering disk 23 is fitted snugly into the upper end of the shell 18 and'is countersunk in its central portion to conform to the top plate 22, said disk preferably contacting with the under surface of said top plate throughout its entire area. As previously indicated, the periphery of the flared portion 16 of the retaining member is vsubstantially horizontal, and on such annular surface is mounted a row or ring 24 or" bearing balls, which balls contact with and support the circumfercm` tial portion of the centern r disk 23. This circumferential portion is horizontal and is of greater width than the diameter of the assente Y' balls 24 so that said balls have some freedom ot lateral movement and cannot receive lateral pinch or strain from the countersunk portion of said disk, which countersunk portion extends below the horizontal axis otl said balls and prevents accidental removal ot' said balls from their course. lt is the function of 'the series of balls 24 to carry all of the load or downward pressure exerted through the top plate, and object carried thereby, to the wheel-carrying yoke and members. The disk 23 serves to strengthen and reinforce the upper end of the shell 18 and prevent buckling or collapse thereof in use under heavy strains, and also increases balls 24: which carry the load.

litwill be observed that both rows of balls 20 and 2l are relatively large in diameter, extending outside of and beyond the vertical plane of the axis of the wheel 10. This increases the ellective bearing surface', lessens wear and extends the period ot' usefulness of the device, and also lessons the leverage and strain produced when the caster is traveling over obstructions or rough surfaces. No downward pressure would be applied to the lowermost balls 20 except perhaps temporar-ily when a serious or relatively great obstruction is encountered by the wheel, which obstruction would have to be so great as to lift the load upon the upper balls 241 at the rear of the ring and away from the upper balls in front, before the outer rim of the portion 16 could press downwardly upon the lower balls 20 in front.

ln Fig. 1 the top plate and flange 21 of the shell are shown apertured in alinement and connected by means of a plurality of hollow rivets 25, which in this instance are tapered. The top plate and flange 2l may be ot' the same size and shape, one form being shown in Fig. Il, and the top plate is adapted to be secured in any desired manner to a load object. When constructed as shown in Fig. 1, the securing means may be passed upwardly through the hollow rivets 25 into the load object.

f A different fastening means between the top plate and `shell is shown in Figs. 2 and 4l, in which the horizontal flange 21 rof the latter member is omitted. ln this construci :smooth upper surface for the top plate.

ln Figs. 2 and 3 a still further form 'is shown 1n which the shell 18 is formed with two diametrically opposite, relatively narrow flanges 29, 30 at its top, extendingont-y wardly. The top plate 22 is formed with diametrically opposite projections 31, 32, and in the operation of assembling the parts these projectins are "bent and pressed over and around the flanges 29, 30 of the shell, as shown in Fig. 3, to secure said members together.

In Fing. a form isshown which is ularly adaptable when the shell i8 top plate 22 are formed by pressing and stamping, saidv members being formed more as shown and described in connection with Figa 1, that is to say with registering holes in the top plate and the vhorizontal flange 2l of the shell. (lne of said members may be formed with a bur 3l around the hole therein, whichbur is adapted to be extend!- ed' into a hole in the other member `and there riveted or upset so as to secure the n'nembers together.

Either of ,the forms illustrated and def scribed may be employed 'for connecting the,

shell and,v top plate, and in some instances, if deemed necessary for strength, two of the forms may be employed conjunctively and as complementary to each other, as shown in Fig. 4.

No dirt or other foreign substances can enter the caster from the top, 'on account ot the protection affordedby the imperorate top plate, and as the annular space between the lower llange 19 of the shell and the retraining member is very narrow, and opens fupwardly, there is little danger of foreign substances entering' by that route.

At times the top plate may be made by casting from metal, in which event the disk 23 may be made integral therewith, in which form as to fit down snugly and tightly Within the' upper end of the shell, as shown in Fig. 6;

A standard form and size of upper structure, including the top plate, shell and retaining member, with the anti-friction devices therein, may be used with a variety of sizes and shapes of Wheel supporting yokes, and such yokes may carry wheelsgof single, double or multiple construction and of any desired size and shape. This makes for 'economy in production and facility of adaptation to various uses.

The space within the cupped retaining member 15-16 is ample for a sufficient quantity ot grease to lubricate the movable parts over a long period, which grease works, in. use, into the racoways and between the bearing balls.

The parts are separable, by removal of the bolt or screw 17, thus facilitating the replacement of worn or broken parts and lengthening the life of the whole device.

l claim as my invention- 1. A swivel caster, comprising av wheel partire"L and yoke, a wheel journaled therein, a retaining `member mounted'on and tilted rigidlyfto said wheel yoke and havingan outwardly projecting liang'eportion, a shell mounted conccntrically of said-retaining member and having at its lower end a llange projecting beneath the flange portion thereof, bearing; balls between said [lange and.' flange portion adapted to receive lateral pressure only, a

`said top plate to said shell, a disk pressed rigidly and snugly into the upper end of vsaid shell beneath said top plate, said disk ,'being countersunk in its central portion whereby an annular peripheral horizontal track is formed, and a series of bearing balls mounted between said annularV peripheral track and the flange portion of .the retaining member, said annular peripheral track being of greater width than the diameter of said balls whereby the latter receive downumrd` pressure only.

Q swivel caster, comprising a wheel yoke, a wheel pivoted therein, a retaining member mounted on and fixed ripidly to said wheel yoke and having` an outwardlyv projecting' flange portion terminating in an annular peripheral horizontal track, a shell mounted concentrically of said retaining member andhaving at its lower margin a llange projecting inwardly beneath the flange portion oil." said retaining member, a series ot bearingv balls between said flange and flange portion adapted to receive lateral pressure only, a top plate on said shell, means for securing;r said top plate to said shell, a disk mounted snugly within the upper end oi said shell in contact with said top plate, said top plate and disk being countersunk in their central portions and formed with an annular plane portion circumiierentially of said counter-sink, and a series ot bearingf balls between the annular plane portion ot said disk and the annular horizontal track portion of'said retaining nxe'mber, the annular plane port-ion of said disk being 'wider than the diameter ot said latter balls, whereby said balls ha ve a treedoin of lateral movement and receive down ward pressure only.

3. .ln a swivel caster, a wheel yoke, a wheel pi'voted therein and trailing relative to the vertical airis of said caster, a retaining meinber of circular toxin secured rigidly on said wheel yoke, a. shell mounted concentrically of said retaining member and formed with a flange at its lower margin extending` beneath said retaining member, a row ot' bear ing balls on said flange and contactinff said retaining" member, said balls adapted to receive lateral pressure only, a top plate on and secured to said shell, a row oft balls on said retaining member in contact with said top plate and receiving vertical pressure only, both rows of balls being-ot' relatively topplate on saidy shell, means for securing' large diameter and extending outside of the vertical plane of the axis of rotation of said wheel. 4 l

4. In a swivel caster, a wheel yoke, a wheel pivoted therein, a circular retaining member secured rigidly on said wheel yoke, said retaining member being formed with an upwardly and outwardly extending flangeV portion, a shell mounted concentrically of said retaining member 'and formed :1t-'its lower margin with a flange extending inwardly beneath the flange portion of said retaining member, a series of balls` mounted between said flange and flange portion and contacting concaved surfaces thereof, said flange and flange portion each extending beond said balls on substantially horizontal lines parallel with and spaced from lines tangential to said balls, whereby pressure is exerted on Said balls on oblique lines and said balls receive lateral strain and pressure only, a top plate on and secured to the upper end of said shell, and another row oi bearing balls between said retaining member and top plate receiving vertical pressure only.

5. In a swivel -aster, a cylindrical shell, means for attaching said shell to a load object, a wheel yoke and wheel pivoted therein, a member secured to said yoke and extending within and rotatable relative to said Langere shell, anti-friction devices between said shell and member, a disk fitting snugly within the upper end of Said shell, and anti-frietion devices between said disk and said member.

6. In a swivel caster, a wheel yoke, a wheel pivoted therein, said yoke having a circular horizontal portion at its top, a retaining member having ya circular portion contacting with such horizontal portionrof the yoke, a

screw or bolt rigidly securing said members` together centrally of' their contacting portions, said retaining member also extending upwardly and outwardly in a flange portion, a shell mounted ooncentrically of said retaining member and adapted to be secured to a load object, said shell being formed at its lower margin with an inwardly projecting flange beneath the flange portion of said retaining member, bearing balls in a relatively large ring between said flange and flange portion, a disk mounted rigidly in the upper end of' said shell, and bearing balls in a relatively large ringbetween said flange portion and disk.

Signed at Des Moines, in the county of Polk and State o-lowa, this 8 day of April, 1921.

JoHN LoUciEN cHEsNUTT. 

